Recovering vanadium oxides from oil



Patented May 24, 1938 PATENT OFFICE RECOVEBING VANADIUM OXIDES FROM OIL -Hendrik Jan Jakob Ja'nssen, The Hague, Netherlands, assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. Application October 13, 1936, Se-

rial No. 105,399. In the Netherlands October 3 Claims. (Cl. 2317) This invention relates to a process for the production of metals, in particular vanadium, or metal compounds from oils containing metal compounds. It is known that various crude mineral oils contain small quantities of metal generally in the form of organic compounds. There exist, for example, crude oils containing small amounts of vanadium, tungsten and nickel. Compounds of various metals may sometimes occur in the same crude oil. When residual oil such as fuel oil containing such metals or metal compounds is subject to combustion in the usual manner in a furnace, the metals and metal compounds presentare chiefly converted into the corresponding metal oxides. These oxides have been recovered from the ashes collecting in the bottom of the furnace. Upon further investigation it has been found that by far the greater quantity of the metallic oxides pass up the flue as combustion dust. For example, when using a Venezuelan residual oil as fuel it was found that approximately 95% of the vanadium passed up the flue as combustion dust.

It is an object of this invention to devise a process by which metal compounds present in flue gases from the combustion of fuel containing metal compounds may be recovered.

It is a further object of this invention to so control the particle size of the solids produced in the combustion gases that they may be readily separated from the flue gases and the metal oxides removed. Besides ensuring that the particle size of solids is not so small that the same will be carried along with the flue gases up the chimney, it is also important to ensure that the particle size is not so large that the material becomes deposited in the furnace.

Now it has been found that the dimensions of the ash particles containing metal oxides can be controlled within desired limits for separation in a cyclone by regulating the size of the oil droplets issuing from the burner. Thismay be carried various ways. Firstly, the size of the oil drop can be regulated by increasing or decreasing the viscosity of the oil passing to the burner. increase in droplet size being effected by an increase in the viscosity of the oil and vice Versa, a decrease in droplet size being effected by a decrease in the viscosity of the oil. In turn the viscosity may be varied by regulating the degree of preheating given to the oil.

Another method of arriving at a drop of uniform desired size is by the use of a suitable atomizer preferably of the hollow jet and central return type. According to the invention, the size of the drop is preferably controlled by both a proper selection and correct adjustment of the atomizer and adjustment of the viscosity of the oil.

Now'it has been found that flue ash particles having a diameter of more than 300 microns are too large to be properly carried along by the flue gas and separated by means of a cyclone whereas particles having a diameter of 10 microns or smaller are in general too small to be collected to a satisfactory extent by the usual cyclones. When burning a Venezuelan vanadium containing oil residue having an ash-content of about 8 kilograms per ton (including 6 kilograms nonburned carbon) the following calculation can be made: assuming the specific gravity of the ash and of the residue to be 1, then 8 kilograms ash per ton residue correspond to 8 litres flue ash per 1000 litres residue, i. e. one drop of oil, one

unit of length in diameter corresponds to a flue ash globule: in

unit of length in diameter.

The diameter of the flue ash particle can be measured with the aid of a microscope so that from the value found the diameter of the drops of oil can be deduced in the manner indicated above. The above mentioned admissible upper and lower limit of the size of the flue ash particles therefore correspond to a diameter of oil drops of maximum 1000-1500 microns and minimum of 50 microns respectively.

The size of the oil drops is preferably adjusted in such a manner by means of one of the methods mentioned above that the diameter of the flue ash particles is about 100-200 microns.

Tests have proved that by regulating the size of the flue ash particles in the manner described more than 90% of the vanadium contained in the asphalt can be separated off as flue ash.

In order to eflect a further recovery, the bricks lining the furnace and flue may have a glazedsurface such as for example, as acid proof brick, in order to prevent some of the flue dust, which at the high temperatures occurring in the furnace is in a liquid state, from penetrating into the brick or fluxing therewith.

If the furnace and flue are lined with porous brick then appreciable amounts of metal can be recovered by periodically removing the lining, grinding the same and treating the brick with chlorine. Vanadium can, for example, be so obtained in the form of the volatile chlorides or oxy chlorides.

I claim as my invention:

1. In a process for the recovery of metals from mineral oils containing the same, the steps of atomizing said oil, effecting combustion of said atomized oil in a furnace continually producing flue ash particles substantially all of from 100 to 200 microns in diameter separating the said flue ash particles from the flue gas stream by means of a cyclone separator and thereafter recovering metal from said particles.

2. In a process for the recovery of vanadium atomized oil in a furnace, continually producing flue ash particles substantially all of from 100 to 200 microns in diameter, separating said flue ash particles from the flue gas stream by means of a cyclone separator and recovering vanadium oxide from said particles.

3. In a process for the recovery of vanadium from Venezuelan and similar petroleum oils the stepof atomizing said oil, effecting combustion of said atomized oil in a furnace, continually producing flue ash particles substantially all of from 100 to 200 microns in diameter, separating said flue ash particles from the flue gas stream by means of a cyclone separator and recovering vanadium oxide from said particles. 

